24F vs. 60i data... at DVinfo.net

Paul Chiappini · June 1st, 2006, 10:32 AM

Does anyone know if HDV on the XLH1 in 24f is less prone to macroblocking than 60i? If 24f is derived via pulldown, then probably not.

Just wondering,
Paul

Barlow Elton · June 1st, 2006, 02:12 PM

It is slightly less prone because of two things:

1) Progressive Encoding: Much more efficient than interlace material.

2) 24 fps recording: There are no actual pulldown frames recorded to tape and therefore using up precious bandwidth in HDV 24F, only digital repeat flags that tell the decoder to repeat frames upon firewire output or do a 3:2 pulldown out the SDI port

Bottom Line: it looks great

Paul Chiappini · June 1st, 2006, 05:54 PM

Barlow,

Thanks for the info. I asked because I saw Steven Dempsey's "Rain." I believe that he normally shoots 24f, but this looked 1080i. A few of the shots looked like they really broke down w/ blocking artifacts, and I haven't seen that in any of his previous posts.

Barlow Elton · June 1st, 2006, 06:14 PM

Two things I think:

--It had a bug which rendered a 1080i (looking) 29.97fps clip upon output
--It was rendered with another pass of 25mbs MPEG2 which will definitely be challenged with such intricate motion. The clip actually went through 3 passes of compression: HDV, Cineform, and then HDV again.

I think it's better to output to high quality wmv or h.264 at bit rates approaching that of HDV.

Steven Dempsey · June 1st, 2006, 07:24 PM

No macroblocking in the original footage. Barlow is right in his summation.

June 1st, 2006, 10:32 AM	#1
Paul Chiappini Regular Crew Join Date: Feb 2006 Location: Idaho Posts: 89	24F vs. 60i data... Does anyone know if HDV on the XLH1 in 24f is less prone to macroblocking than 60i? If 24f is derived via pulldown, then probably not. Just wondering, Paul

June 1st, 2006, 07:24 PM	#5
Steven Dempsey Disjecta Join Date: Apr 2004 Location: Seattle, Washington Posts: 937	No macroblocking in the original footage. Barlow is right in his summation. __________________ Try my Digital Therapy: http://www.pinelakefilms.com/digital_therapy.html Films on ExposureRoom: http://exposureroom.com/members/disjecta.aspx/videos/

June 1st, 2006, 02:12 PM	#2
Barlow Elton Major Player Join Date: Mar 2005 Location: UT Posts: 945	It is slightly less prone because of two things: 1) Progressive Encoding: Much more efficient than interlace material. 2) 24 fps recording: There are no actual pulldown frames recorded to tape and therefore using up precious bandwidth in HDV 24F, only digital repeat flags that tell the decoder to repeat frames upon firewire output or do a 3:2 pulldown out the SDI port Bottom Line: it looks great

June 1st, 2006, 05:54 PM	#3
Paul Chiappini Regular Crew Join Date: Feb 2006 Location: Idaho Posts: 89	Barlow, Thanks for the info. I asked because I saw Steven Dempsey's "Rain." I believe that he normally shoots 24f, but this looked 1080i. A few of the shots looked like they really broke down w/ blocking artifacts, and I haven't seen that in any of his previous posts.

June 1st, 2006, 06:14 PM	#4
Barlow Elton Major Player Join Date: Mar 2005 Location: UT Posts: 945	Two things I think: --It had a bug which rendered a 1080i (looking) 29.97fps clip upon output --It was rendered with another pass of 25mbs MPEG2 which will definitely be challenged with such intricate motion. The clip actually went through 3 passes of compression: HDV, Cineform, and then HDV again. I think it's better to output to high quality wmv or h.264 at bit rates approaching that of HDV.